The argument day is not right

datepart

Is the part of startdate and enddate that specifies the type of boundary crossed. The following table lists all valid datepart arguments. User-defined variable equivalents are not valid.

datepart	Abbreviations
year	yy, yyyy
quarter	qq, q
month	mm, m
dayofyear	dy, y
day	dd, d
week	wk, ww
hour	hh
minute	mi, n
second	ss, s
millisecond	ms
microsecond	mcs
nanosecond	ns